Boston’s first-in-the-nation net zero carbon zoning rule for new buildings passed Jan. 29 after failing to gain enough votes last year.

The city’s zoning commission approved the rule requiring most new developments to attain net zero carbon emissions when they open or the property owners will be fined—the most stringent carbon emissions rule for buildings in the nation, according to a statement released by Mayor Michelle Wu’s office.

The new zoning sets a net zero emissions standard for new projects filed after July 1, 2025, the city says. That includes 15 units or more, a minimum of 20,000 sq. ft., or additions of at least 50,000 square feet or more to existing buildings. It excludes small additions, renovations and adaptive reuse projects. Additionally, the measure provides life sciences labs until 2035, and new hospitals and manufacturing plants until 2045 to comply.

Last year a vote on the identical mandate fell one vote short of the seven votes necessary for a two-thirds majority. The measure passed this year after Wu fired former Zoning Commission chair Jay Hurley, a former leader of the Iron Workers Local 7 union, who voted against the measure. Wu also added two new members to her board. Hurley has alleged Wu fired him in retaliation for voting no.

Wu says the measure will help the city achieve its carbon-neutral goal by 2050.

But NAIOP Massachusetts, a chapter of the Commercial Real Estate Development Association, and other organizations are concerned the rule comes on the heels of other Boston ordinances and could increase development costs, the Boston Business Journal reports. The Building Emissions Reduction and Disclosure Ordinance (BERDO) adopted in 2024, for example, requires large buildings to reduce greenhouse gas emissions.

Going net zero carbon cause prices to rise for construction. I bet Boston feels really good for being ahead of the ball and protecting it neighborhood from climate change. Admiral indeed but is it a fool’s solution? Does the cost justify the benefit?